Tool holder



FIG. 1 is a left side elevational view of a tool holder showing my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a bottom plan view;

FIG. 4 is a top plan view;

FIG. 5 is a left front perspective view; and

FIG. 6 is a rear elevational view. 

The ornamental design for a tool holder, as shown and described. 